The present disclosure relates to an image reading device that includes a reading unit coupled with a flat cable.
An image reading device includes a reading unit that includes: a reading sensor such as a CIS in which a plurality of imaging elements are arranged in a main scanning direction; a light-emitting element, such as an LED, configured to emit light to an imaging target; and optical components such as a lens and a mirror. The image reading device has a transparent, flat plate-like contact member, wherein a document sheet, from which an image is to be read, is placed on an upper surface of the contact member. The reading unit is configured to be reciprocally moved along the back surface of the contact member in a housing of the image reading device. The reading unit reads an image from a document sheet by, while moving, irradiating light toward the back surface of the contact member and receiving reflection light thereof. A flexible-type flat cable (hereinafter referred to as “FFC”) is connected to the reading unit, and control signals and data are communicated between the reading unit and a control portion via the FFC.
Since the reading unit reciprocally moves in the housing as described above, the FFC is stored in the housing in a bent state forming the shape of letter U in a cross section so that it can follow the movement of the reading unit. When the reading unit moves, the FFC expands and contracts following the movement of the reading unit, while keeping the bent state. The FFC has a repulsive force (restoring force) against the bending, and thus, when the reading unit moves to a position distanced from a bending part of the FFC, the bending part becomes large due to the repulsive force and the bending part may contact the back surface of the contact member. In connection with this, if the housing is made tall to accommodate the maximum size of the bending part, the size of the housing in the height direction becomes large. There are known some configurations conceived for the problem to be solved. For example, there is known a configuration where the reading unit is provided with a pressing portion for separating the FFC from the contact member. In addition, there is known a configuration where the FFC extends out diagonally downward from a connection portion between the reading unit and the FFC.